1. A method by a base station of a mobile communication system, the method comprising:identifying downlink control information including first information related to scheduling data, second information on a second reference signal of a cell associated with the base station being quasi co-located with a first reference signal of an interference signal, and third information on a scrambling sequence of the first reference signal of the interference signal; and
transmitting, to a terminal, the identified downlink control information,
wherein the first reference signal of the interference signal comprises a demodulation reference signal (DMRS) of the interference signal, and
wherein the second reference signal of the cell associated with the base station further comprises at least one of a channel status information reference signal (CSI-RS) and a cell-specific reference signal (CRS).